However, the public and internal lists suffers three damages.
First damage: because of leaks, everything slightly confidential or even controversial is no more discussed. Neither on public, nor on private lists. Consequence: decrease of list volume
Second damage: the staff of WMF grew larger and does not discuss much on lists. So, many topics which used to be discussed on lists are now discussed in office. Consequence: decrease of list volume
Third damage: internal lists are quite cabalistic :-) Just consider internal-l and see how many new members joined in 2006 ? in 2007 ? in 2008 ? I think by and large, most people who joined in 2008 are staff members. Or previous members who were at risk of being removed because they stopped being staff or board members. Proposition of new names is looked with serious suspicion. New blood is now extremely rare, and does not replace those who become inactive. Consequence: decrease of list volume
I do not really understand your third reason, but may be it is not that important. But the first two seem to me to touch a very important issue - what should be actually the content of the mailing lists. I do not think it is a good idea to discuss confidential issues in any public communication channel, including mailing lists (but also including other channels like blogs or whatever). On the other hand, in the example of the board members discussing more things in the office - well, if these things are not intended for non-members, they should not be discussed in public anyway, and whether the Board members or staff choose to discuss it in the office, by phone, in the closed mailing list or secure intrernet forum is entirely their business. On the other hand, if they start discussing in private things which should be discussed by the community, I do not find this a good idea. I realize of course that certain (in fact, most of) initiatives can be only prepared as a part of private communication, since the signal to noise ration of any public cnahhel is too low, and public discussion may be not so efficient at the brainstorming phase. But these initiatives should be discussed in public after they get prepared, and I am afraid this is what now slowly retreats from the mailing lists.
Cheers Yaroslav